<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Class.php 24032 2011-05-10 21:08:20Z mabe $
 */

/**
 * @see Zend_Cache_Core
 */
require_once 'Zend/Cache/Core.php';

/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cache_Frontend_Class extends Zend_Cache_Core {
	/**
	 * Available options
	 *
	 * ====> (mixed) cached_entity :
	 * - if set to a class name, we will cache an abstract class and will use only static calls
	 * - if set to an object, we will cache this object methods
	 *
	 * ====> (boolean) cache_by_default :
	 * - if true, method calls will be cached by default
	 *
	 * ====> (array) cached_methods :
	 * - an array of method names which will be cached (even if cache_by_default = false)
	 *
	 * ====> (array) non_cached_methods :
	 * - an array of method names which won't be cached (even if cache_by_default = true)
	 *
	 * @var array available options
	 */
	protected $_specificOptions = array ('cached_entity' => null, 'cache_by_default' => true, 'cached_methods' => array (), 'non_cached_methods' => array () );
	
	/**
	 * Tags array
	 *
	 * @var array
	 */
	private $_tags = array ();
	
	/**
	 * SpecificLifetime value
	 *
	 * false => no specific life time
	 *
	 * @var int
	 */
	private $_specificLifetime = false;
	
	/**
	 * The cached object or the name of the cached abstract class
	 *
	 * @var mixed
	 */
	private $_cachedEntity = null;
	
	/**
	 * The class name of the cached object or cached abstract class
	 *
	 * Used to differentiate between different classes with the same method calls.
	 *
	 * @var string
	 */
	private $_cachedEntityLabel = '';
	
	/**
	 * Priority (used by some particular backends)
	 *
	 * @var int
	 */
	private $_priority = 8;
	
	/**
	 * Constructor
	 *
	 * @param  array $options Associative array of options
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	public function __construct(array $options = array()) {
		while ( list ( $name, $value ) = each ( $options ) ) {
			$this->setOption ( $name, $value );
		}
		if ($this->_specificOptions ['cached_entity'] === null) {
			Zend_Cache::throwException ( 'cached_entity must be set !' );
		}
		$this->setCachedEntity ( $this->_specificOptions ['cached_entity'] );
		$this->setOption ( 'automatic_serialization', true );
	}
	
	/**
	 * Set a specific life time
	 *
	 * @param  int $specificLifetime
	 * @return void
	 */
	public function setSpecificLifetime($specificLifetime = false) {
		$this->_specificLifetime = $specificLifetime;
	}
	
	/**
	 * Set the priority (used by some particular backends)
	 *
	 * @param int $priority integer between 0 (very low priority) and 10 (maximum priority)
	 */
	public function setPriority($priority) {
		$this->_priority = $priority;
	}
	
	/**
	 * Public frontend to set an option
	 *
	 * Just a wrapper to get a specific behaviour for cached_entity
	 *
	 * @param  string $name  Name of the option
	 * @param  mixed  $value Value of the option
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	public function setOption($name, $value) {
		if ($name == 'cached_entity') {
			$this->setCachedEntity ( $value );
		} else {
			parent::setOption ( $name, $value );
		}
	}
	
	/**
	 * Specific method to set the cachedEntity
	 *
	 * if set to a class name, we will cache an abstract class and will use only static calls
	 * if set to an object, we will cache this object methods
	 *
	 * @param mixed $cachedEntity
	 */
	public function setCachedEntity($cachedEntity) {
		if (! is_string ( $cachedEntity ) && ! is_object ( $cachedEntity )) {
			Zend_Cache::throwException ( 'cached_entity must be an object or a class name' );
		}
		$this->_cachedEntity = $cachedEntity;
		$this->_specificOptions ['cached_entity'] = $cachedEntity;
		if (is_string ( $this->_cachedEntity )) {
			$this->_cachedEntityLabel = $this->_cachedEntity;
		} else {
			$ro = new ReflectionObject ( $this->_cachedEntity );
			$this->_cachedEntityLabel = $ro->getName ();
		}
	}
	
	/**
	 * Set the cache array
	 *
	 * @param  array $tags
	 * @return void
	 */
	public function setTagsArray($tags = array()) {
		$this->_tags = $tags;
	}
	
	/**
	 * Main method : call the specified method or get the result from cache
	 *
	 * @param  string $name       Method name
	 * @param  array  $parameters Method parameters
	 * @return mixed Result
	 */
	public function __call($name, $parameters) {
		$callback = array ($this->_cachedEntity, $name );
		
		if (! is_callable ( $callback, false )) {
			Zend_Cache::throwException ( 'Invalid callback' );
		}
		
		$cacheBool1 = $this->_specificOptions ['cache_by_default'];
		$cacheBool2 = in_array ( $name, $this->_specificOptions ['cached_methods'] );
		$cacheBool3 = in_array ( $name, $this->_specificOptions ['non_cached_methods'] );
		$cache = (($cacheBool1 || $cacheBool2) && (! $cacheBool3));
		if (! $cache) {
			// We do not have not cache
			return call_user_func_array ( $callback, $parameters );
		}
		
		$id = $this->_makeId ( $name, $parameters );
		if (($rs = $this->load ( $id )) && isset ( $rs [0], $rs [1] )) {
			// A cache is available
			$output = $rs [0];
			$return = $rs [1];
		} else {
			// A cache is not available (or not valid for this frontend)
			ob_start ();
			ob_implicit_flush ( false );
			
			try {
				$return = call_user_func_array ( $callback, $parameters );
				$output = ob_get_clean ();
				$data = array ($output, $return );
				$this->save ( $data, $id, $this->_tags, $this->_specificLifetime, $this->_priority );
			} catch ( Exception $e ) {
				ob_end_clean ();
				throw $e;
			}
		}
		
		echo $output;
		return $return;
	}
	
	/**
	 * ZF-9970
	 *
	 * @deprecated
	 */
	private function _makeId($name, $args) {
		return $this->makeId ( $name, $args );
	}
	
	/**
	 * Make a cache id from the method name and parameters
	 *
	 * @param  string $name Method name
	 * @param  array  $args Method parameters
	 * @return string Cache id
	 */
	public function makeId($name, array $args = array()) {
		return md5 ( $this->_cachedEntityLabel . '__' . $name . '__' . serialize ( $args ) );
	}

}
